Zoom lens and imaging apparatus

ABSTRACT

A zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a positive fifth lens group. During zooming from a wide angle end to a telephoto end, the first lens group is fixed relative to an image surface, and distances between the respective lens groups change in predetermined manners. The second lens group consists of predetermined four lens components.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of International Application No. PCT/JP2017/009143, filed Mar. 8, 2017, the disclosure of which is incorporated herein by reference in its entirety. Further, this application claims priority from Japanese Patent Application No.2016-065233, filed Mar. 29, 2016, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a zoom lens suitable for an electronic camera, such as a digital camera, a video camera, a broadcast camera, a motion-picture camera, or a surveillance camera; and also relates to an imaging apparatus including the zoom lens.

2. Description of the Related Art

A zoom lens is suggested in JP2015-212723A, as a zoom lens used for an electronic camera, such as a digital camera, a video camera, a broadcast camera, a motion-picture camera, or a surveillance camera.

SUMMARY OF THE INVENTION

However, the F-number of the lens of JP2015-212723A at a telephoto end is not sufficiently small, and thus a zoom lens having high magnification and a small F-number at the telephoto end is demanded.

The invention is made in light of the situations, and it is an object of the invention to provide a high-performance zoom lens which has high magnification and a small F-number at a telephoto end, and whose aberrations have been properly corrected; and an imaging apparatus including the zoom lens.

A zoom lens according to an aspect of the invention consists of, in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive refractive power; during zooming, the first lens group is fixed relative to an image surface; during zooming from a wide angle end to a telephoto end, a distance between the first lens group and the second lens group constantly increases, a distance between the second lens group and the third lens group constantly decreases, and a distance between the third lens group and the fourth lens group at the telephoto end is smaller than a distance between the third lens group and the fourth lens group at the wide angle end; the second lens group consists of, in order from the object side, a first lens component, a second lens component, a third lens component, and a fourth lens component; the first lens component is a 2a negative lens having a concave surface that faces an image side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the object side of the 2a negative lens; the second lens component is a cemented lens in which a 2bn biconcave lens and a 2bp positive meniscus lens are cemented in that order from the object side and which entirely has a negative refractive power; the third lens component is a cemented lens in which a 2cn biconcave lens and a 2cp positive lens are cemented in that order from the object side; and the fourth lens component is a 2d negative lens having a concave surface that faces the object side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the image side of the 2d negative lens.

With the zoom lens according to the invention, during zooming, the fifth lens group is preferably fixed relative to the image surface; and during zooming from the wide angle end to the telephoto end, a 3-4 composite lens group composed of the third lens group and the fourth lens group, and the second lens group preferably simultaneously pass through respective points at which imaging magnifications of the 3-4 composite lens group and the second lens group are −1.

During zooming from the wide angle end to the telephoto end, the distance between the third lens group and the fourth lens group preferably decreases, increases, and then decreases.

The 2a negative lens is preferably a meniscus lens.

The following conditional expression (1) is preferably satisfied, and the following conditional expression (1-1) is further preferably satisfied

−1<(L2bpr+L2cnf)/(L2bpr-L2cnf)<1   (1), and

−0.6<(L2bpr+L2cnf)/(L2bpr-L2cnf)<0.6   (1-1),

where

L2bpr is a curvature radius of a surface on the image side of the 2bp positive meniscus lens, and

L2cnf is a curvature radius of a surface on the object side of the 2cn biconcave lens.

The following conditional expressions (2) and (3) are preferably satisfied, and the following conditional expression (2-1) and/or conditional expression (3-1) are further preferably satisfied

0.2 <f2/f2a<0.6   (2),

0.1<f2/f2b<0.6   (3), and

0.25<f2/f2a<0.55   (2-1), and/or

0.2<f2/f2b<0.5   (3-1),

where

f2 is a focal length for a d-line of the second lens group,

f2a is a focal length for the d-line of the first lens component, and

f2b is a focal length for the d-line of the second lens component.

The following conditional expression (4) is preferably satisfied, and the following conditional expression (4-1) is further preferably satisfied

−0.3<f2×(f2cp_nd−f2cn_nd)×(1/L2cnp)<−0.1   (4), and

−0.2<f2×(f2cp_nd−f2cn_nd)×(1/L2cnp)<−0.12   (4-1),

where

f2 is the focal length for the d-line of the second lens group,

f2cp_nd is a refractive index for the d-line of the 2cp positive lens,

f2cn_nd is a refractive index for the d-line of the 2cn biconcave lens, and

L2cnp is a curvature radius of a cemented surface of the 2cn biconcave lens and the 2cp positive lens.

The first lens group consists of, in order from the object side, a la lens group fixed relative to the image surface during focusing and having a negative refractive power, a 1 b lens group being movable along an optical axis during focusing and having a positive refractive power, and a 1 c lens group fixed relative to the image surface during focusing and having a positive refractive power; and the 1 c lens group has on the most image side four lenses of, in order from the object side, a positive lens, a cemented lens in which a negative meniscus lens having a convex surface facing the object side and a positive lens are cemented in that order from the object side, and a positive meniscus lens having a convex surface facing the object side.

When the first lens group is composed of the 1a lens group, the 1b lens group, and the 1c lens group, the following conditional expression (5) and conditional expression (6) are preferably satisfied, and the following conditional expression (5-1) and/or conditional expression (6-1) are further preferably satisfied

75<f1c_vd_ave<96   (5),

0.5<f1c_θgF_ave<0.6   (6), and

80<f1c_vd_ave<96   (5-1), and/or

0.52<f1c_θgF_ave<0.56   (6-1),

where

f1c_vd_ave is an average value of Abbe numbers for the d-line of the positive lenses included in the 1 c lens group, and

f1c_θgF_ave is an average value of partial dispersion ratios of the positive lenses included in the 1c lens group.

When the first lens group is composed of the 1a lens group, the 1b lens group, and the 1c lens group, the following conditional expression (7) is preferably satisfied, and the following conditional expression (7-1) is further preferably satisfied

0.8<f1/f1c<1.2   (7), and

0.9<f1/f1c<1.1   (7-1),

where

f1 is a focal length for the d-line of the first lens group, and

f1c is a focal length for the d-line of the 1c lens group.

When the first lens group is composed of the 1a lens group, the 1b lens group, and the 1c lens group, the number of positive lenses included in the 1b lens group and the 1c lens group is preferably five in total.

When the number of positive lenses included in the 1b lens group and the 1c lens group is five in total, the 1b lens group may consist of, in order from the object side, a cemented lens in which a negative meniscus lens and a biconvex lens are cemented in that order from the object side, and a biconvex lens; and the 1c lens group may consist of, in order from the object side, a biconvex lens, a cemented lens in which a negative meniscus lens and a positive meniscus lens are cemented in that order from the object side, and a positive meniscus lens.

When the number of positive lenses included in the 1b lens group and the 1c lens group is five in total, the 1b lens group may consist of a cemented lens in which a negative meniscus lens and a biconvex lens are cemented in that order from the object side; and the 1c lens group may consist of, in order from the object side, a positive lens having a convex surface facing the object side, a positive meniscus lens, a cemented lens in which a negative meniscus lens and a positive meniscus lens are cemented in that order from the object side, and a positive meniscus lens.

When the first lens group is composed of the 1a lens group, the 1b lens group, and the 1c lens group, the 1a lens group preferably consists of, in order from the object side, a negative meniscus lens, a biconcave lens, and a positive lens.

An imaging apparatus according to the invention includes the above-described zoom lens according to the invention.

The aforementioned expression “ consist of . . . ” implies that a lens having no power; optical elements other than a lens, such as a diaphragm, a mask, a cover glass, and a filter; a lens flange; a lens barrel; an imaging element; a mechanism part such as a camera shake correction mechanism; and so forth, may be included in addition to those described as the components.

The sign of the refractive power of any of the aforementioned lens groups, the sign of the refractive power of any of the aforementioned lenses, and the surface shape of any of the lenses are considered in a paraxial region as far as an aspherical surface is included. All the aforementioned conditional expressions use the d-line (wavelength of 587.6 nm) as the reference and use values in focus at infinity unless otherwise noted.

A zoom lens according to the invention consists of, in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive refractive power; during zooming, the first lens group is fixed relative to an image surface; during zooming from a wide angle end to a telephoto end, a distance between the first lens group and the second lens group constantly increases, a distance between the second lens group and the third lens group constantly decreases, and a distance between the third lens group and the fourth lens group at the telephoto end is smaller than a distance between the third lens group and the fourth lens group at the wide angle end; the second lens group consists of, in order from the object side, a first lens component, a second lens component, a third lens component, and a fourth lens component; the first lens component is a 2a negative lens having a concave surface that faces an image side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the object side of the 2a negative lens; the second lens component is a cemented lens in which a 2bn biconcave lens and a 2bp positive meniscus lens are cemented in that order from the object side and which entirely has a negative refractive power; the third lens component is a cemented lens in which a 2cn biconcave lens and a 2cp positive lens are cemented in that order from the object side; and the fourth lens component is a 2d negative lens having a concave surface that faces the object side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the image side of the 2d negative lens. Thus, the zoom lens can be a high-performance zoom lens which has high magnification and a small F-number at the telephoto end, and whose aberrations have been properly corrected.

An imaging apparatus according to the invention includes the zoom lens according to the invention, and thus an image with high magnification and high image quality can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides cross-sectional views illustrating a lens configuration of a zoom lens according to an embodiment (common to Example 1) of the invention;

FIG. 2 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 2 of the invention;

FIG. 3 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 3 of the invention;

FIG. 4 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 4 of the invention;

FIG. 5 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 5 of the invention;

FIG. 6 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 6 of the invention;

FIG. 7 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 7 of the invention;

FIG. 8 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 8 of the invention;

FIG. 9 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 9 of the invention;

FIG. 10 provides cross-sectional views illustrating a lens configuration of a zoom lens according to Example 10 of the invention;

FIG. 11 provides aberration diagrams of the zoom lens according to Example 1 of the invention;

FIG. 12 provides aberration diagrams of the zoom lens according to Example 2 of the invention;

FIG. 13 provides aberration diagrams of the zoom lens according to Example 3 of the invention;

FIG. 14 provides aberration diagrams of the zoom lens according to Example 4 of the invention;

FIG. 15 provides aberration diagrams of the zoom lens according to Example 5 of the invention;

FIG. 16 provides aberration diagrams of the zoom lens according to Example 6 of the invention;

FIG. 17 provides aberration diagrams of the zoom lens according to Example 7 of the invention;

FIG. 18 provides aberration diagrams of the zoom lens according to Example 8 of the invention;

FIG. 19 provides aberration diagrams of the zoom lens according to Example 9 of the invention;

FIG. 20 provides aberration diagrams of the zoom lens according to Example 10 of the invention; and

FIG. 21 is a brief configuration diagram of an imaging apparatus according to an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the invention is described below in detail with reference to the drawings. FIG. 1 provides cross-sectional views illustrating a lens configuration of a zoom lens according to an embodiment of the invention. A configuration example illustrated in FIG. 1 is common to the configuration of a zoom lens according to Example 1 which will be described later. In FIG. 1, the left side is an object side and the right side is an image side. An illustrated aperture diaphragm St does not necessarily indicate the size or shape, but indicates the position on an optical axis Z. FIG. 1 also illustrates an arrow indicative of a movement locus of each lens group during zooming from a wide angle end to a telephoto end, a point at which an imaging magnification is −1 (a horizontal dotted line with β=−1 in the drawing), axial rays wa, and rays wb at the maximum angle of view.

The zoom lens according to this embodiment consists of, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, an aperture diaphragm St, and a fifth lens group G5 having a positive refractive power; and the zoom lens is configured such that, during zooming, the first lens group G1 is fixed relative to an image surface Sim, and during zooming from the wide angle end to the telephoto end, the distance between the first lens group G1 and the second lens group G2 constantly increases, the distance between the second lens group G2 and the third lens group G3 constantly decreases, and the distance between the third lens group G3 and the fourth lens group G4 at the telephoto end is smaller than that at the wide angle end.

When the zoom lens is applied to an imaging apparatus, it is preferable to arrange a cover glass, a prism, and/or any of various filters, such as an infrared cut filter or a low pass filter, between the optical system and the image surface Sim in accordance with a camera configuration on which the lens is mounted. Thus, FIG. 1 illustrates an example in which parallel-plane-shaped optical members PP1 and PP2 that expect the above-listed components are arranged between the lens system and the image surface Sim.

With this configuration, the third lens group G3 and the fourth lens group G4 correct a variation in position of the image surface caused by zooming with respect to the second lens group G2 that acts on zooming, and the third lens group G3 and the fourth lens group G4 relatively move. Thus, field curvature during zooming can be corrected and a variation in spherical aberration during zooming can be properly corrected.

The third lens group G3 and the fourth lens group G4 are configured to move so that the distance therebetween on a telephoto side is smaller than that on a wide angle side. The movement range of the second lens group G2 on the telephoto side can be large, and the refractive power of the second lens group G2 can be suppressed. Thus, a variation in aberration caused by zooming can be suppressed.

The second lens group G2 consists of, in order from the object side, a first lens component, a second lens component, a third lens component, and a fourth lens component; and the first lens component is a 2a negative lens L2 a having a concave surface that faces the image side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the object side of the 2a negative lens L2 a; the second lens component is a cemented lens in which a 2bn biconcave lens L2bn and a 2bp positive meniscus lens L2bp are cemented in that order from the object side and which entirely has a negative refractive power; the third lens component is a cemented lens in which a 2cn biconcave lens L2cn and a 2cp positive lens L2cp are cemented in that order from the object side; and the fourth lens component is a 2d negative lens L2 d having a concave surface that faces the object side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the image side of the 2d negative lens L2 d.

If the second lens group G2 has more than four lens components, the movement range of the second lens group G2 may be hardly secured. If the second lens group G2 has less than four lens components, it is difficult to suppress aberrations. Thus, with the four lens components, the movement range of the second lens group G2 can be secured and aberrations can be suppressed.

To attain high magnification, the principal point position of the second lens group G2 is required to be located at a position closer to the object side, and hence a negative lens is required to be added to the second lens group G2.

Since the first lens component has the above-described configuration, occurrence of distortion and astigmatism on the wide angle side can be suppressed.

The principal point position can be located closer to the object side by arranging the negative lens on the image side of the second lens component; however, lateral chromatic aberration likely occurs on the wide angle side. Owing to this, since the second lens component is the cemented lens of the 2bn biconcave lens L2bn and the 2bp positive meniscus lens L2bp as described above and the cemented lens entirely has the negative refractive power, the lateral chromatic aberration can be corrected while the principal point position is located closer to the object side. Also, if the 2bp positive meniscus lens L2bp has a concave surface on the image side, this is advantageous to widening the angle of view.

Since the second lens component has the concave surface on the image side, for the third lens component, by arranging on the most object side a lens having a concave surface on the object side, occurrence of spherical aberration on the telephoto side can be suppressed. Also, if the cemented lens of the 2cn biconcave lens L2cn and the 2cp positive lens L2cp is employed, axial chromatic aberration on the telephoto side can be corrected.

Since the fourth lens component has the concave surface on the object side, the fourth lens component contributes to correcting astigmatism that occurs due to the first lens group G1 on the wide angle side while suppressing occurrence of spherical aberration on the telephoto side. Also, since the negative lens is employed, the fourth lens component contributes to enhancing the negative refractive power of the entire second lens group G2.

With the zoom lens according to this embodiment, during zooming, the fifth lens group G5 is preferably fixed relative to the image surface Sim, and during zooming from the wide angle end to the telephoto end, a 3-4 composite lens group composed of the third lens group G3 and the fourth lens group G4, and the second lens group G2 preferably simultaneously pass through respective points at which imaging magnifications of the 3-4 composite lens group and the second lens group G2 are −1. With this configuration, the third lens group G3 does not return to the image side and a large zoom ratio can be obtained during zooming from the wide angle end to the telephoto end.

During zooming from the wide angle end to the telephoto end, the distance between the third lens group G3 and the fourth lens group G4 preferably decreases, increases, and then decreases. With this configuration, a variation in field curvature at an intermediate focal length can be suppressed.

The 2a negative lens is preferably a meniscus lens. Since the 2a negative lens has a convex surface on the object side and a concave surface on the image side, this is advantageous to suppressing distortion and astigmatism on the wide angle side, and advantageous to suppressing spherical aberration on the telephoto side.

The following conditional expression (1) is preferably satisfied. As long as below the upper limit of the conditional expression (1), distortion and astigmatism on the wide angle side can be suppressed. As long as above the lower limit of the conditional expression (1), spherical aberration on the telephoto side can be suppressed. If the following conditional expression (1-1) is satisfied, further proper characteristics can be obtained.

−1<(L2bpr+L2cnf)/(L2bpr−L2cnf)<1   (1), and

−0.6<(L2bpr+L2cnf)/(L2bpr−L2cnf)<0.6   (1-1),

where

L2bpr is a curvature radius of a surface on the image side of the 2bp positive meniscus lens, and

L2cnf is a curvature radius of a surface on the object side of the 2cn biconcave lens.

The following conditional expressions (2) and (3) are preferably satisfied. By setting values not to be equal to or more than the upper limits of the conditional expressions (2) and (3), distortion and astigmatism on the wide angle side can be suppressed. By setting values not to be equal to or less than the lower limits of the conditional expressions (2) and (3), the negative refractive power increases, and the principal point position can be located closer to the object side. If the following conditional expression (2-1) and/or conditional expression (3-1) is satisfied, further proper characteristics can be obtained.

0.2<f2/f2a<0.6   (2),

0.1<f2/f2b<0.6   (3), and

0.25<f2/f2a<0.55   (2-1), and/or

0.2<f2/f2b<0.5   (3-1),

where

f2 is a focal length for a d-line of the second lens group,

f2a is a focal length for the d-line of the first lens component, and

f2b is a focal length for the d-line of the second lens component.

The following conditional expression (4) is preferably satisfied. If the conditional expression (4) is satisfied, at a cemented surface of the 2cn biconcave lens L2cn and the 2cp positive lens L2cp, spherical aberration on the telephoto side can be properly corrected. If the following conditional expression (4-1) is satisfied, further proper characteristics can be obtained.

−0.3<f2×(f2cp_nd−f2cn_nd)×(1/L2cnp)<−0.1   (4), and

−0.2<f2×(f2cp_nd−f2cn_nd)×(1/L2cnp)<−0.12   (4-1),

where

f2 is the focal length for the d-line of the second lens group,

f2cp_nd is a refractive index for the d-line of the 2cp positive lens,

f2cn_nd is a refractive index for the d-line of the 2cn biconcave lens, and

L2cnp is a curvature radius of a cemented surface of the 2cn biconcave lens and the 2cp positive lens.

The first lens group G1 preferably consists of, in order from the object side, a 1 a lens group G1 a fixed relative to the image surface Sim during focusing and having a negative refractive power, a 1 b lens group G1 b being movable along the optical axis during focusing and having a positive refractive power, and a 1 c lens group G1 c fixed relative to the image surface Sim during focusing and having a positive refractive power; and the 1 c lens group G1 c preferably has on the most image side four lenses of, in order from the object side, a positive lens, a cemented lens in which a negative meniscus lens having a convex surface facing the object side and a positive lens are cemented in that order from the object side, and a positive meniscus lens having a convex surface facing the object side.

Since the first lens group G1 is composed of the above-described 1 a lens group G1 a, 1 b lens group G1 b, and 1 c lens group G1 c, this contributes to reduction in spherical aberration, axial chromatic aberration, and variation in the angle of view caused by downsizing and/or focusing.

Since the 1 c lens group G1 c has the above-described configuration and spherical aberration of marginal rays on the telephoto side is properly corrected, the F-number can be decreased while high magnification is attained. Specifically, marginal rays on the telephoto side become convergent rays due to the positive lens on the most object side among the four lenses. The convergent rays are incident on the negative meniscus lens next to that positive lens, and hence spherical aberration is not excessively corrected. The convergent rays are also incident on the positive meniscus lens, and hence spherical aberration is not excessively corrected. Thus, the spherical aberration can be properly corrected.

When the first lens group G1 is composed of the 1 a lens group G1 a , the 1 b lens group G1 b, and the 1 c lens group G1 c, the following conditional expressions (5) and (6) are preferably satisfied. If Abbe numbers and partial dispersion ratios of the positive lenses included in the 1 c lens group G1 c satisfy the conditional expressions (5) and (6), axial chromatic aberration and secondary spectrum on the telephoto side can be simultaneously properly corrected. If the following conditional expression (5-1) and/or conditional expression (6-1) are satisfied, further proper characteristics can be obtained.

75<f1c_vd_ave<96   (5),

0.5<f1c_θgF_ave<0.6   (6), and

80<f1c_vd_ave<96   (5-1), and/or

0.52<f1c_θgF_ave<0.56   (6-1),

where

f1c_vd_ave is an average value of Abbe numbers for the d-line of the positive lenses included in the 1 c lens group, and

f1c_θgF_ave is an average value of partial dispersion ratios of the positive lenses included in the 1 c lens group.

When the first lens group G1 is composed of the 1 a lens group G1 a , the 1 b lens group G1 b, and the 1 c lens group G1 c, the following conditional expression (7) is preferably satisfied. As long as below the upper limit of the conditional expression (7), spherical aberration can be properly corrected. As long as above the lower limit of the conditional expression (7), the back focus of the first lens group G1 can be increased, and even for a high-magnification lens, the power of the second lens group G2 can be suppressed. Thus, occurrence of aberrations due to the second lens group G2 can be suppressed. If the following conditional expression (7-1) is satisfied, further proper characteristics can be obtained.

0.8<f1/f1c<1.2   (7), and

0.9<f1/f1c<1.1   (7-1),

where

f1 is a focal length for the d-line of the first lens group, and

f1c is a focal length for the d-line of the 1 c lens group.

When the first lens group G1 is composed of the 1 a lens group G1 a , the 1 b lens group G1 b, and the 1 c lens group G1 c, spherical aberration can be more easily corrected as the number of positive lenses included in the 1 b lens group G1 b and the 1 c lens group G1 c increases; however, it is difficult to secure a stroke during focusing. Thus, the number of positive lenses included in the 1 b lens group G1 b and the 1 c lens group G1 c is preferably five in total. With this configuration, the spherical aberration can be corrected and the stroke during focusing can be secured.

When the number of positive lenses included in the 1 b lens group G1 b and the 1 c lens group G1 c is five in total, the 1 b lens group G1 b may consist of, in order from the object side, a cemented lens in which a negative meniscus lens and a biconvex lens are cemented in that order from the object side, and a biconvex lens; and the 1 c lens group G1 c may consist of, in order from the object side, a biconvex lens, a cemented lens in which a negative meniscus lens and a positive meniscus lens are cemented in that order from the object side, and a positive meniscus lens.

With this configuration, the power of the 1 b lens group G1 b can be increased, and the height of marginal rays incident on the 1 c lens group G1 c can be decreased. Thus, even when the F-number is small, the configuration is advantageous to downsizing.

When the number of positive lenses included in the 1 b lens group G1 b and the 1 c lens group G1 c is five in total, the 1 b lens group G1 b may consist of a cemented lens in which a negative meniscus lens and a biconvex lens are cemented in that order from the object side; and the 1 c lens group G1 c may consist of, in order from the object side, a positive lens having a convex surface facing the object side, a positive meniscus lens, a cemented lens in which a negative meniscus lens and a positive meniscus lens are cemented in that order from the object side, and a positive meniscus lens.

With this configuration, the power of the 1 c lens group G1 c can be increased, and the power of the 1 b lens group G1 b can be decreased. Thus, aberrations during variation in focus, in particular, variation in spherical aberration can be suppressed.

When the first lens group G1 is composed of the 1a lens group G1 a, the 1 b lens group G1 b, and the 1 c lens group G1 c, the 1a lens group G1 a preferably consists of, in order from the object side, a negative meniscus lens, a biconcave lens, and a positive lens. With this configuration, distortion on the wide angle side, and spherical aberration on the telephoto side can be properly corrected.

When the first lens group G1 is composed of the 1 a lens group G1 a, the 1 b lens group G1 b, and the 1 c lens group G1 c, the 1 a lens group G1 a preferably consists of, in order from the object side, a first negative lens, a second negative lens, and a positive lens, and preferably satisfies the following conditional expression (8). Since the 1a lens group G1 a has the above-described configuration, the angle of chief rays of a peripheral angle of view incident on the 1 b lens group G1 b can be decreased, and occurrence of astigmatism due to the 1 b lens group G1 b and later can be reduced. Since the conditional expression (8) is satisfied, variation in field curvature during zooming can be reduced, and further spherical aberration on the telephoto side can be accommodated within a proper range. If the following conditional expression (8-1) is satisfied, further proper characteristics can be obtained.

−0.8<(L1ar+L1bf)/(L1ar−L1bf)<−0.04   (8), and

−0.5<(L1ar+L1bf)/(L1ar−L1bf)<−0.04   (8-1),

where

L1ar is a curvature radius of a surface on the image side of the first negative lens, and

L1bf is a curvature radius of a surface on the object side of the second negative lens.

When the 1 a lens group G1 a consists of, in order from the object side, the first negative lens, the second negative lens, and the positive lens, the 1 a lens group G1 a preferably satisfies the following conditional expression (9). As long as below the upper limit of the conditional expression (9), spherical aberration on the telephoto side can be reduced. As long as above the lower limit of the conditional expression (9), a sufficient negative power can be given to an air lens that is formed between the first negative lens and the second negative lens, and hence spherical aberration on the telephoto side can be reduced. If the following conditional expression (9-1) is satisfied, further proper characteristics can be obtained.

0.04<d2/tt1<0.15   (9), and

0.06<d2/tt1<0.12   (9-1),

where

d2 is a distance between the first negative lens and the second negative lens, and

tt1 is a length on the optical axis of the first lens group.

While FIG. 1 illustrates the example in which the optical members PP1 and PP2 are arranged between the lens system and the image surface Sim, instead of arranging any of various filters, such as a low pass filter or one that cuts a specific wavelength range, between the lens system and the image surface Sim, such various filters may be arranged between respective lenses, or a lens surface of any of the lenses may be treated with a coating having an effect similar to those of the various filters.

Next, numerical examples of the zoom lens according to the invention are described.

A zoom lens according to Example 1 is described first. FIG. 1 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 1. In FIG. 1, and FIGS. 2 to 10 corresponding to Examples 2 to 10, the left side is an object side and the right side is an image side. An illustrated aperture diaphragm St does not necessarily indicate the size or shape, but indicates the position on an optical axis Z. FIG. 1 also illustrates an arrow indicative of a movement locus of each lens group during zooming from a wide angle end to a telephoto end, a point at which an imaging magnification is −1 (a horizontal dotted line with β=−1 in the drawing), axial rays wa, and rays wb at the maximum angle of view.

The zoom lens according to Example 1 is composed of, in order from the object side, a first lens G1 consisting of ten lenses of a lens L1 a to a lens L1 j and entirely having a positive refractive power, a second lens group G2 consisting of six lenses of a lens L2 a to a lens L2 d and entirely having a negative refractive power, a third lens group G3 consisting of three lenses of a lens L3 a to a lens L3 c and entirely having a positive refractive power, a fourth lens group G4 consisting of three lenses of a lens L4 a to a lens L4 c and entirely having a positive refractive power, and a fifth lens group G5 consisting of fifteen lenses of a lens L5a to a lens L5 o and entirely having a positive refractive power.

The first lens group G1 is composed of a 1a lens group G1 a consisting of three lenses of the lens L1 a to the lens L1 c, a 1 b lens group G1 b consisting of three lenses of the lens L1 d to the lens L 1 f, and a 1 c lens group G1 c consisting of four lenses of the lens L1 g to the lens L1 j.

Table 1 shows basic lens data of the zoom lens according to Example 1, Table 2 shows data relating to specifications, Table 3 shows data relating to surface distances that change during zooming, and Table 4 shows data relating to aspherical coefficients. The meaning of reference signs in the table are exemplarily described below according to Example 1, and reference signs according to Examples 2 to 10 are basically similar to those according to Example 1.

In the lens data in Table 1, the column of surface number indicates surface numbers that sequentially increase toward the image side while a surface of a component on the most object side is counted as the first surface, the column of curvature radius indicates a curvature radius of each surface, and the column of surface distance indicates a distance between each surface and a surface next thereto on the optical axis Z. Also, the column of nd indicates a refractive index for the d-line (wavelength of 587.6 nm) of each optical element, the column of vd indicates an Abbe number for the d-line (wavelength of 587.6 nm) of each optical element, and the column of θgF indicates a partial dispersion ratio of each optical element.

The partial dispersion ratio θgF is expressed by the following expression

θgF=(ng−nF)/(nF−nC)

where

ng is a refractive index for a g-line,

nF is a refractive index for an F-line, and

nC is a refractive index for a C-line.

In this case, the sign of the curvature radius is positive when the surface shape is convex on the object side, and negative when the surface shape is convex on the image side. The basic lens data includes the aperture diaphragm St and the optical members PP1 and PP2. A word “diaphragm” together with the surface number thereof is written in a cell of a surface corresponding to the aperture diaphragm St in the column of surface number. In the lens data in Table 1, DD [surface number] is written in a cell of the column of surface distance if the distance changes during zooming. The numerical value corresponding to DD [surface number] is shown in Table 3.

For data relating to specifications in Table 2, values of zoom magnification, focal length f, F-number FNo., and total angle of view 2ω are shown.

In the basic lens data, data relating to specifications, and data relating to surface distances that change, the unit of angle is degree, and the unit of length is millimeter; however, since the optical system can be used although the optical system is proportionally expanded or proportionally contracted, other suitable units may be used.

In the lens data in Table 1, an asterisk * is added to a surface number of an aspherical surface, and a numerical value of a paraxial curvature radius is indicated as a curvature radius of the aspherical surface. The data relating to aspherical coefficients in Table 4 indicates a surface number of an aspherical surface, and an aspherical coefficient relating to the aspherical surface. A numerical value “E±n” (n is an integer) of an aspherical coefficient represents “×10^(±n).” The aspherical coefficient is a value of each of coefficients KA, Am (m=3 . . . 16) expressed by the following aspherical surface expression

Zd=C·h ²/{1+(1−KA·C ₂ ·h ²)^(1/2)}+ΣAm·h^(m)

where

Zd is an aspherical surface depth (a length of a perpendicular line extending from a point on an aspherical surface at a height h to a plane perpendicular to the optical axis with which the vertex of the aspherical surface comes into contact),

h is a height (a distance from the optical axis),

C is a reciprocal of a paraxial curvature radius, and

KA, Am each are an aspherical coefficient (m=3 . . . 16).

TABLE 1 Example 1, lens data (nd, νd for d-line) Surface Curvature Surface number radius distance nd νd θgF  1 −13378.35006 5.977 1.77250 49.60 0.55212  2 506.33763 16.475  3 −584.49773 4.800 1.80400 46.58 0.55730  4 335.43813 2.500  5 349.09925 12.000 1.84139 24.56 0.61274  6 8435.34081 4.877  7 7849.07545 5.000 1.80000 29.84 0.60178  8 439.82608 18.270 1.49700 81.54 0.53748  9 −444.99046 0.125  10 1000.00000 10.877 1.63246 63.77 0.54215  11 −1249.86489 34.999  12 336.67292 23.000 1.43387 95.18 0.53733  13 −555.44540 1.838  14 224.29284 6.264 1.63980 34.47 0.59233  15 143.35462 28.031 1.43875 94.94 0.53433  16 8626.60879 3.144  17 176.57760 17.500 1.49700 81.54 0.53748  18 475.02631 DD [18]  19 182.61414 4.500 1.95375 32.32 0.59015  20 86.38802 12.791  21 −331.30207 3.073 1.55032 75.50 0.54001  22 61.69495 4.501 1.54814 45.78 0.56859  23 78.10163 9.831  24 −145.36707 2.145 1.49700 81.54 0.53748  25 96.62937 7.000 1.84139 24.56 0.61274  26 −687.33596 5.926  27 −76.16819 2.130 1.43875 94.94 0.53433  28 1644.59414 DD [28]  29 4104.02749 7.091 1.43875 94.66 0.53402  30 −137.72084 0.177  31 2020.97885 7.824 1.43875 94.66 0.53402  32 −125.76283 2.257 1.94692 32.77 0.58862  33 −185.59421 DD [33]  34 124.45199 6.891 1.80390 32.49 0.59305  35 90.80287 10.021 1.43875 94.66 0.53402  36 −49972.97817 2.118  37 817.29840 6.060 1.43875 94.66 0.53402 *38 −343.72331 DD [38]  39 ∞ 7.705 (diaphragm)  40 −170.68031 4.420 1.51793 61.26 0.54257  41 1424.66641 1.393  42 854.58215 4.351 1.84139 24.56 0.61274  43 −298.35856 3.656 1.83481 42.72 0.56486  44 408.16101 22.581  45 −124.70799 2.963 1.63723 35.15 0.58660  46 545.65832 5.104 1.84139 24.56 0.61274  47 −188.00072 0.570  48 59.62634 5.814 1.73532 53.96 0.54449  49 1199.51213 3.520 1.72395 29.02 0.60094  50 86.05183 19.251  51 144.47442 7.880 1.74356 40.77 0.57416  52 −63.44339 2.500 1.92486 36.38 0.57719  53 99.00655 14.855  54 342.36858 5.042 1.84139 24.56 0.61274  55 −97.66651 13.086  56 222.75255 4.531 1.52189 50.90 0.55751  57 21.13645 6.601 1.49700 81.54 0.53748  58 48.14182 8.035  59 95.08701 6.958 1.49700 81.54 0.53748  60 −37.48307 2.876 1.95375 32.32 0.59015  61 −260.67641 9.976  62 55.91542 4.808 1.53515 57.90 0.54800  63 −387.96848 2.000  64 ∞ 1.500 1.51633 64.14 0.53531  65 ∞ 0.000  66 ∞ 3.690 1.51633 64.14 0.53531  67 ∞ 35.589

TABLE 2 Example 1, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom 1.0 3.8 19.8 magnification f′ 34.993 134.373 692.862 FNo. 2.85 2.85 4.85 2ω[°] 44.8 11.8 2.4

TABLE 3 Example 1, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 5.430 85.787 118.419 DD [28] 231.414 131.867 2.255 DD [33] 24.452 5.861 2.307 DD [38] 2.654 40.435 140.970

TABLE 4 Example 1, aspherical coefficient Surface number 38 KA −6.0660447E+00 A3 0.0000000E+00 A4 −2.8516819E−09 A5 −3.7645381E−10 A6 5.1922095E−11 A7 −1.9515833E−13 A8 4.9687016E−14 A9 −1.0574536E−14 A10 2.5263117E−17 A11 2.5847685E−17 A12 −7.1492956E−19 A13 3.0977491E−21 A14 −1.5830950E−22 A15 9.3185221E−24 A16 −1.0801038E−25

FIG. 11 provides aberration diagrams of the zoom lens according to Example 1. Spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the wide angle end are shown in FIG. 11 in order from the left side in the upper section. Spherical aberration, astigmatism, distortion, and lateral chromatic aberration at an intermediate position are shown in FIG. 11 in order from the left side in the middle section. Spherical aberration, astigmatism, distortion, and lateral chromatic aberration at the telephoto end are shown in FIG. 11 in order from the left side in the lower section. The aberration diagrams show states when the object distance is infinity. The aberration diagrams showing spherical aberration, astigmatism, and distortion show aberrations using the d-line (wavelength of 587.6 nm) as the reference wavelength. The spherical aberration diagram shows aberrations for the d-line (wavelength of 587.6 nm), C-line (wavelength of 656.3 nm), F-line (wavelength of 486.1 nm), and g-line (wavelength of 435.8 nm) by respectively using solid line, long dotted line, short dotted line, and gray solid line. The astigmatism diagram shows aberrations in a sagittal direction and a tangential direction by respectively using solid line and short dotted line. The lateral chromatic aberration diagram shows aberrations for the C-line (wavelength of 656.3 nm), F-line (wavelength of 486.1 nm), and g-line (wavelength of 435.8 nm) by respectively using long dotted line, short dotted line, and gray solid line. Note that FNo. in the spherical aberration diagram indicates an F-number, and co in the other aberration diagrams indicates a half angle of view.

A zoom lens according to Example 2 is described next. FIG. 2 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 2. The zoom lens according to Example 2 has the same lens number configuration as that of the zoom lens according to Example 1. Table 5 shows basic lens data of the zoom lens according to Example 2, Table 6 shows data relating to specifications, Table 7 shows data relating to surface distances that change, and Table 8 shows data relating to aspherical coefficients. FIG. 12 shows aberrations.

TABLE 5 Example 2, lens data (nd, νd for d-line) Surface Curvature Surface number radius distance nd νd θgF  1 −17374.27699 4.954 1.77250 49.60 0.55212  2 515.52725 16.475  3 −565.78121 4.800 1.80400 46.58 0.55730  4 334.28184 2.500  5 348.58721 12.000 1.84139 24.56 0.61274  6 7335.08162 4.857  7 8100.03388 5.000 1.80000 29.84 0.60178  8 441.57926 18.270 1.49700 81.54 0.53748  9 −459.45313 0.125  10 999.62577 10.863 1.63246 63.77 0.54215  11 −1249.85366 34.988  12 331.41864 23.000 1.43387 95.18 0.53733  13 −555.43460 1.844  14 231.27593 6.246 1.72047 34.71 0.58350  15 143.34892 28.057 1.49700 81.54 0.53748  16 4763.22108 3.150  17 179.29715 17.500 1.49700 81.54 0.53748  18 457.42906 DD [18]  19 182.44776 4.500 1.95375 32.32 0.59015  20 86.51118 12.791  21 −334.16437 3.072 1.55032 75.50 0.54001  22 61.82805 4.500 1.54814 45.78 0.56859  23 78.16316 9.822  24 −145.45264 2.145 1.49700 81.54 0.53748  25 96.79029 7.009 1.84139 24.56 0.61274  26 −694.72543 5.941  27 −76.19334 2.141 1.43875 94.94 0.53433  28 1736.83551 DD [28]  29 4270.48200 7.105 1.43875 94.66 0.53402  30 −137.86493 0.194  31 2057.62397 7.841 1.43875 94.66 0.53402  32 −126.04188 2.251 1.94709 32.76 0.58864  33 −185.50599 DD [33]  34 124.39046 6.894 1.80391 32.49 0.59304  35 90.81996 10.020 1.43875 94.66 0.53402  36 −169144.05304 2.114  37 824.45845 6.056 1.43875 94.66 0.53402 *38 −346.58355 DD [38]  39 ∞ 7.698 (diaphragm)  40 −170.85337 4.409 1.51792 61.26 0.54256  41 1412.02444 1.380  42 849.25112 4.339 1.84139 24.56 0.61274  43 −295.14207 3.651 1.83481 42.72 0.56486  44 407.32585 22.575  45 −124.60852 2.955 1.63728 35.13 0.58662  46 549.68268 5.099 1.84139 24.56 0.61274  47 −188.55815 0.573  48 59.52609 5.815 1.73548 53.96 0.54449  49 1254.27053 3.520 1.72380 29.01 0.60096  50 86.04201 19.247  51 144.55821 7.876 1.74390 40.78 0.57413  52 −63.49507 2.500 1.92466 36.38 0.57721  53 99.04128 14.838  54 347.50320 5.029 1.84139 24.56 0.61274  55 −97.91525 13.073  56 222.40660 4.518 1.52047 51.16 0.55705  57 21.11965 6.594 1.49700 81.54 0.53748  58 48.22752 8.032  59 94.79522 6.951 1.49700 81.54 0.53748  60 −37.49466 2.868 1.95375 32.32 0.59015  61 −259.55822 9.975  62 55.77235 4.807 1.53634 57.80 0.54818  63 −380.90253 2.000  64 ∞ 1.500 1.51633 64.14 0.53531  65 ∞ 0.000  66 ∞ 3.690 1.51633 64.14 0.53531  67 ∞ 35.589

TABLE 6 Example 2, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom 1.0 3.8 19.8 magnification f′ 34.992 134.370 692.844 FNo. 2.85 2.85 4.85 2ω[°] 44.8 11.8 2.4

TABLE 7 Example 2, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 7.414 87.953 120.637 DD [28] 231.897 132.146 2.241 DD [33] 24.482 5.853 2.287 DD [38] 2.530 40.369 141.157

TABLE 8 Example 2, aspherical coefficient Surface number 38 KA −6.0661247E+00 A3 0.0000000E+00 A4 −6.0498397E−10 A5 −3.9242470E−10 A6 4.2998199E−11 A7 6.5777538E−15 A8 6.1474104E−14 A9 −1.0495812E−14 A10 1.5144561E−17 A11 2.4967345E−17 A12 −7.1763341E−19 A13 5.0602365E−21 A14 −1.7779216E−22 A15 8.3996059E−24 A16 −9.3643011E−26

A zoom lens according to Example 3 is described next. FIG. 3 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 3. The zoom lens according to Example 3 has the same lens number configuration as that of the zoom lens according to Example 1. Table 9 shows basic lens data of the zoom lens according to Example 3, Table 10 shows data relating to specifications, Table 11 shows data relating to surface distances that change, and Table 12 shows data relating to aspherical coefficients. FIG. 13 shows aberrations.

TABLE 9 Example 3, lens data (nd, νd for d-line) Surface Curvature Surface number radius distance nd νd θgF  1 31335.06747 5.980 1.77250 49.60 0.55212  2 489.39985 16.475  3 −607.98263 4.800 1.80400 46.58 0.55730  4 338.23443 2.500  5 351.80001 12.000 1.84139 24.56 0.61274  6 5645.25277 4.829  7 5037.54253 5.000 1.80000 29.84 0.60178  8 416.86150 18.270 1.49700 81.54 0.53748  9 −440.71712 0.125  10 999.99521 10.829 1.63246 63.77 0.54215  11 −1249.81060 35.076  12 341.50810 23.000 1.43387 95.18 0.53733  13 −555.44540 1.826  14 218.29118 6.257 1.62004 36.26 0.58800  15 143.35678 28.012 1.43875 94.94 0.53433  16 9804.77077 3.126  17 172.79153 17.500 1.43875 94.94 0.53433  18 472.57533 DD [18]  19 184.30388 4.485 1.95375 32.32 0.59015  20 86.21375 12.779  21 −327.42076 3.061 1.55032 75.50 0.54001  22 61.43736 4.500 1.54814 45.78 0.56859  23 77.86458 9.830  24 −144.01651 2.155 1.49700 81.54 0.53748  25 96.10729 7.000 1.84139 24.56 0.61274  26 −679.42572 5.898  27 −75.75003 2.125 1.43875 94.94 0.53433  28 1478.43455 DD [28]  29 4567.42296 7.086 1.43875 94.66 0.53402  30 −138.46671 0.166  31 2111.50348 7.813 1.43875 94.66 0.53402  32 −126.19862 2.268 1.94652 32.80 0.58853  33 −185.32437 DD [33]  34 124.52210 6.889 1.80381 32.49 0.59305  35 90.89636 10.023 1.43875 94.66 0.53402  36 −186927.49799 2.117  37 829.24124 6.060 1.43875 94.66 0.53402 *38 −343.97598 DD [38]  39 ∞ 7.702 (diaphragm)  40 −170.75799 4.421 1.51777 61.27 0.54254  41 1475.89688 1.393  42 850.55831 4.352 1.84139 24.56 0.61274  43 −305.31634 3.654 1.83481 42.72 0.56486  44 413.48017 22.576  45 −124.89221 2.963 1.63709 35.15 0.58659  46 549.68685 5.103 1.84139 24.56 0.61274  47 −187.85314 0.562  48 59.64886 5.814 1.73577 53.93 0.54453  49 1254.69959 3.520 1.72411 29.00 0.60099  50 86.06614 19.253  51 144.26045 7.882 1.74352 40.78 0.57414  52 −63.37168 2.504 1.92475 36.38 0.57718  53 98.95567 14.864  54 341.41408 5.047 1.84139 24.56 0.61274  55 −97.75851 13.082  56 221.61374 4.531 1.52295 50.71 0.55785  57 21.13749 6.600 1.49700 81.54 0.53748  58 48.16130 8.031  59 94.87124 6.958 1.49700 81.54 0.53748  60 −37.45970 2.870 1.95375 32.32 0.59015  61 −258.87634 9.967  62 55.96570 4.807 1.53491 57.92 0.54796  63 −390.17281 2.000  64 ∞ 1.500 1.51633 64.14 0.53531  65 ∞ 0.000  66 ∞ 3.690 1.51633 64.14 0.53531  67 ∞ 35.273

TABLE 10 Example 3, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom 1.0 3.8 20.0 magnification f′ 34.989 134.359 699.788 FNo. 2.85 2.85 4.85 2ω[°] 44.4 11.8 2.2

TABLE 11 Example 3, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 5.867 85.721 118.204 DD [28] 232.487 133.483 3.402 DD [33] 24.441 5.855 2.323 DD [38] 2.695 40.431 141.560

TABLE 12 Example 3, aspherical coefficient Surface number 38 KA −6.0659990E+00   A3 0.0000000E+00 A4 7.5934682E−09 A5 −1.2082285E−09   A6 5.9533640E−11 A7 5.6310087E−14 A8 6.4475101E−14 A9 −1.0442256E−14   A10 6.3094636E−17 A11 2.0953831E−17 A12 −6.5812003E−19   A13 5.7283785E−21 A14 −1.3871386E−22   A15 6.1553364E−24 A16 −6.9270089E−26  

A zoom lens according to Example 4 is described next. FIG. 4 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 4.

The zoom lens according to Example 4 differs from the zoom lens according to Example 1 only for the lens number configuration of a first lens group G1. The first lens group G1 is composed of a 1 a lens group G1 a consisting of three lenses of a lens L1 a to a lens L1 c, a 1 b lens group G1 b consisting of two lenses of a lens L1 d and a lens L1 e, and a 1 c lens group G1 c consisting of five lenses of a lens L1 f to a lens L1 j.

Table 13 shows basic lens data of the zoom lens according to Example 4, Table 14 shows data relating to specifications, Table 15 shows data relating to surface distances that change, and Table 16 shows data relating to aspherical coefficients. FIG. 14 shows aberrations.

TABLE 13 Example 4, lens data (nd, νd for d-line) Surface number Curvature radius Surface distance nd νd θgF  1 1203.32487 4.400 1.88300 40.76 0.56679  2 388.55765 22.500  3 −592.83878 4.400 1.65113 55.89 0.54672  4 307.63955 3.009  5 329.25013 13.266 1.84139 24.56 0.61274  6 1422.51599 2.995  7 1227.16435 7.230 1.54072 47.23 0.56511  8 303.53553 28.076 1.43875 94.94 0.53433  9 −436.87379 47.872 10 411.84229 11.251 1.69400 56.29 0.54506 11 ∞ 8.520 12 221.02501 20.000 1.43387 95.18 0.53733 13 3784.25046 0.250 14 253.15612 7.500 1.69895 30.05 0.60290 15 127.15122 30.030 1.43875 94.94 0.53433 16 2555.29938 5.000 17 168.85857 11.910 1.49700 81.54 0.53748 18 385.87126 DD [18] 19 2766.24481 3.250 1.71299 53.87 0.54587 20 64.32982 12.471 21 −200.04038 1.820 1.83481 42.72 0.56486 22 131.40042 3.000 1.84139 24.56 0.61274 23 227.27773 4.788 24 −263.90206 2.032 1.49700 81.54 0.53748 25 96.99160 7.818 1.78472 25.68 0.61621 26 −394.03764 5.500 27 −97.99682 2.000 1.43875 94.94 0.53433 28 −2704.70097 DD [28] 29 571.03169 7.574 1.43875 94.66 0.53402 30 −175.34201 0.125 31 −5273.85855 9.925 1.43875 94.66 0.53402 32 −99.81994 3.000 1.80000 29.84 0.60178 33 −143.78222 DD [33] 34 288.39088 4.000 1.80000 29.84 0.60178 35 189.38496 6.545 1.43875 94.66 0.53402 36 −1294.84337 0.757 37 195.15150 9.750 1.43875 94.66 0.53402 *38  −3419.85116 DD [38] 39 (diaphragm) ∞ 7.602 40 −154.21325 1.520 1.83481 42.72 0.56486 41 1055.59942 2.568 1.84139 24.56 0.61274 42 −481.20610 0.200 43 75.70122 4.890 1.56384 60.83 0.54082 44 242.81541 36.671 45 −2628.86635 2.000 1.80610 33.27 0.58845 46 97.76108 3.437 47 −173.65554 2.443 1.95906 17.47 0.65993 48 −87.49658 0.300 49 52.59563 5.624 1.77250 49.62 0.55186 50 −130.79828 1.306 1.53172 48.84 0.56558 51 39.25083 4.064 52 −1280.59765 4.032 1.63854 55.38 0.54858 53 −44.12784 1.000 1.95375 32.32 0.59015 54 121.20174 13.118 55 119.12162 4.416 1.84139 24.56 0.61274 56 −95.72269 8.375 57 −129.53488 3.388 1.51200 52.12 0.56018 58 20.51211 18.000 1.49700 81.54 0.53748 59 36.16294 2.323 60 58.70246 7.174 1.49700 81.54 0.53748 61 −42.75542 1.526 2.00100 29.13 0.59952 62 −166.65679 10.250 63 51.72062 6.662 1.51742 52.43 0.55649 64 −117.33300 2.000 65 ∞ 1.500 1.51633 64.14 0.53531 66 ∞ 0.000 67 ∞ 3.690 1.51633 64.14 0.53531 68 ∞ 33.477

TABLE 14 Example 4, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom 1.0 3.8 19.6 magnification f′ 34.589 132.822 677.946 FNo. 2.85 2.85 4.76 2ω[°] 45.4 12.0 2.4

TABLE 15 Example 4, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 8.534 82.112 114.634 DD [28] 242.787 134.807 4.410 DD [33] 9.113 3.407 2.249 DD [38] 2.730 42.838 141.870

TABLE 16 Example 4, aspherical coefficient Surface number 38 KA 1.0000000E+00 A3 0.0000000E+00 A4 −4.7142041E−08   A5 2.3491920E−08 A6 −4.2313783E−09   A7 4.0862089E−10 A8 −2.4055326E−11   A9 9.6758230E−13 A10 −2.9523189E−14   A11 6.1417894E−16 A12 6.1911610E−19 A13 −5.8240543E−19   A14 1.9090551E−20 A15 −2.7279816E−22   A16 1.5134108E−24

A zoom lens according to Example 5 is described next. FIG. 5 provides cross-sectional sectional views illustrating a lens configuration of the zoom lens according to Example 5. The zoom lens according to Example 5 has the same lens number configuration as that of the zoom lens according to Example 4. Table 17 shows basic lens data of the zoom lens according to Example 5, Table 18 shows data relating to specifications, Table 19 shows data relating to surface distances that change, and Table 20 shows data relating to aspherical coefficients. FIG. 15 shows aberrations.

TABLE 17 Example 5, lens data (nd, νd for d-line) Surface number Curvature radius Surface distance nd νd θgF  1 1274.22298 4.400 1.88300 40.76 0.56679  2 326.74501 19.684  3 −548.17143 4.400 1.65113 55.89 0.54672  4 279.55876 2.619  5 295.45890 12.485 1.84139 24.56 0.61274  6 1744.32995 4.294  7 2819.10370 5.030 1.54072 47.23 0.56511  8 353.73687 25.000 1.43875 94.94 0.53433  9 −334.96231 38.468 10 364.50249 12.791 1.69400 56.29 0.54506 11 ∞ 4.393 12 222.74581 18.826 1.43387 95.18 0.53733 13 3082.74950 0.165 14 303.40519 5.054 1.69895 30.05 0.60290 15 132.44104 29.250 1.43875 94.94 0.53433 16 3846.74680 5.000 17 169.82659 13.641 1.49700 81.54 0.53748 18 483.48570 DD [18] 19 617.86280 2.977 1.71299 53.87 0.54587 20 65.00898 11.459 21 −503.11416 1.820 1.83481 42.72 0.56486 22 153.06550 3.000 1.84139 24.56 0.61274 23 298.42399 5.513 24 −159.10770 2.032 1.49700 81.54 0.53748 25 96.50142 7.218 1.78472 25.68 0.61621 26 −681.45993 7.903 27 −83.70584 2.000 1.43875 94.94 0.53433 28 637.96362 DD [28] 29 2166.99695 6.963 1.43875 94.66 0.53402 30 −161.11101 0.125 31 −405.05862 7.540 1.43875 94.66 0.53402 32 −105.61287 3.000 1.80000 29.84 0.60178 33 −144.13129 DD [33] 34 242.43997 4.431 1.80000 29.84 0.60178 35 151.75864 7.723 1.43875 94.66 0.53402 36 −2815.57106 0.757 37 181.60265 10.556 1.43875 94.66 0.53402 *38  −377.38727 DD [38] 39 (diaphragm) ∞ 9.860 40 −133.65484 1.520 1.83481 42.72 0.56486 41 288.73885 3.709 1.84139 24.56 0.61274 42 −382.22988 0.632 43 78.52091 6.301 1.57328 61.52 0.54253 44 155.19645 37.811 45 1799.38883 2.114 1.78321 25.97 0.60975 46 87.15520 3.914 47 −531.25079 3.149 1.82905 26.59 0.60918 48 −100.44400 0.393 49 55.45392 8.694 1.71006 50.50 0.55448 50 −119.85496 1.310 1.56200 43.51 0.57039 51 47.74047 3.703 52 551.26851 4.508 1.62780 49.87 0.56027 53 −52.32986 1.000 1.94317 33.43 0.58644 54 142.62331 12.620 55 118.28005 4.603 1.85354 22.52 0.62153 56 −106.22412 9.303 57 −4540.69688 5.705 1.51772 55.43 0.55082 58 20.05508 10.796 1.49700 81.54 0.53748 59 35.96189 4.756 60 65.96374 12.822 1.49700 81.54 0.53748 61 −42.55351 1.200 1.96979 30.71 0.59530 62 −2057.26456 8.437 63 60.38503 5.578 1.53899 52.35 0.55624 64 −107.26704 2.000 65 ∞ 1.500 1.51633 64.14 0.53531 66 ∞ 0.000 67 ∞ 3.690 1.51633 64.05 0.53463 68 ∞ 33.854

TABLE 18 Example 5, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom 1.0 3.8 19.6 magnification f′ 34.658 133.088 679.304 FNo. 2.85 2.85 4.75 2ω[°] 44.8 11.8 2.4

TABLE 19 Example 5, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 2.263 82.338 117.906 DD [28] 234.237 130.599 6.030 DD [33] 31.332 11.588 2.249 DD [38] 5.447 48.754 147.095

TABLE 20 Example 5, aspherical coefficient Surface number 38 KA 1.0000000E+00 A3 0.0000000E+00 A4 2.5373147E−08 A5 −3.1896159E−09   A6 4.9719239E−10 A7 −3.4019825E−11   A8 9.1983859E−13 A9 1.0565892E−14 A10 −1.3331255E−15   A11 3.5450551E−17 A12 −6.1939046E−19   A13 1.7369551E−20 A14 −4.7811217E−22   A15 6.8387262E−24 A16 −3.7656702E−26  

A zoom lens according to Example 6 is described next. FIG. 6 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 6. The zoom lens according to Example 6 has the same lens number configuration as that of the zoom lens according to Example 4. Table 21 shows basic lens data of the zoom lens according to Example 6, Table 22 shows data relating to specifications, Table 23 shows data relating to surface distances that change, and Table 24 shows data relating to aspherical coefficients. FIG. 16 shows aberrations.

TABLE 21 Example 6, lens data (nd, νd for d-line) Surface number Curvature radius Surface distance nd νd θgF  1 2216.47396 4.400 1.88300 40.76 0.56679  2 348.74419 21.647  3 −456.42458 4.400 1.65113 55.89 0.54672  4 335.83718 2.549  5 355.21879 13.626 1.84139 24.56 0.61274  6 −16713.99573 2.832  7 2387.81519 7.230 1.54072 47.23 0.56511  8 355.83781 26.378 1.43875 94.94 0.53433  9 −327.41035 38.235 10 379.42749 12.852 1.69400 56.29 0.54506 11 ∞ 1.200 12 221.02097 20.000 1.43387 95.18 0.53733 13 3782.88841 0.204 14 308.20464 7.227 1.69895 30.05 0.60290 15 132.61749 28.875 1.43875 94.94 0.53433 16 1868.31531 4.272 17 169.86664 13.502 1.49700 81.54 0.53748 18 430.57733 DD [18] 19 1103.58993 3.250 1.71299 53.87 0.54587 20 68.01115 11.907 21 −326.98300 1.820 1.83481 42.72 0.56486 22 169.63947 2.628 1.84139 24.56 0.61274 23 290.89410 5.315 24 −168.64444 2.032 1.49700 81.54 0.53748 25 102.42927 7.392 1.78472 25.68 0.61621 26 −400.80737 5.500 27 −89.08531 2.000 1.43875 94.94 0.53433 28 591.05707 DD [28] 29 1022.51482 6.867 1.43875 94.66 0.53402 30 −173.29128 0.125 31 −963.77281 8.813 1.43875 94.66 0.53402 32 −103.46118 3.000 1.80000 29.84 0.60178 33 −145.63723 DD [33] 34 307.20795 4.000 1.80000 29.84 0.60178 35 187.24071 6.734 1.43875 94.66 0.53402 36 −1295.29211 0.757 37 190.80292 9.750 1.43875 94.66 0.53402 *38  −574.80733 DD [38] 39 (diaphragm) ∞ 7.835 40 −157.05449 1.520 1.83481 42.72 0.56486 41 729.25837 2.638 1.84139 24.56 0.61274 42 −554.56625 1.173 43 75.91858 5.086 1.56384 60.83 0.54082 44 249.98807 41.357 45 −3774.71446 2.000 1.80610 33.27 0.58845 46 94.85869 3.623 47 −173.43860 2.415 1.95906 17.47 0.65993 48 −86.94731 2.606 49 51.63691 5.569 1.77250 49.62 0.55186 50 −119.22975 1.220 1.53172 48.84 0.56558 51 38.99544 3.956 52 −1598.56178 3.981 1.63854 55.38 0.54858 53 −42.95369 1.264 1.95375 32.32 0.59015 54 107.69108 13.785 55 117.37581 4.235 1.84139 24.56 0.61274 56 −98.37784 8.474 57 −144.27087 3.922 1.51200 52.12 0.56018 58 21.27734 17.951 1.49700 81.54 0.53748 59 36.86550 2.070 60 54.29072 7.322 1.49700 81.54 0.53748 61 −46.00893 1.200 2.00100 29.13 0.59952 62 −179.99726 10.250 63 46.73203 6.560 1.51742 52.43 0.55649 64 −180.74015 2.000 65 ∞ 1.500 1.51633 64.14 0.53531 66 ∞ 0.000 67 ∞ 3.690 1.51633 64.05 0.53463 68 ∞ 32.967

TABLE 22 Example 6, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom 1.0 3.8 19.6 magnification f′ 35.510 136.357 695.987 FNo. 2.86 2.86 4.75 2ω[°] 44.2 11.8 2.4

TABLE 23 Example 6, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 7.151 86.917 122.100 DD [28] 241.513 134.564 5.603 DD [33] 24.459 8.405 2.178 DD [38] 2.711 45.948 145.953

TABLE 24 Example 6, aspherical coefficient Surface number 38 KA 1.0000000E+00 A3 0.0000000E+00 A4 4.7590627E−09 A5 1.7107487E−09 A6 −2.7096195E−10   A7 2.4286712E−11 A8 −1.2588015E−12   A9 3.9012037E−14 A10 −9.7460038E−16   A11 3.1118871E−17 A12 −6.6381916E−19   A13 −7.9197859E−21   A14 7.3028040E−22 A15 −1.3743077E−23   A16 8.7579813E−26

A zoom lens according to Example 7 is described next. FIG. 7 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 7. The zoom lens according to Example 7 has the same lens number configuration as that of the zoom lens according to Example 4. Table 25 shows basic lens data of the zoom lens according to Example 7, Table 26 shows data relating to specifications, Table 27 shows data relating to surface distances that change, and Table 28 shows data relating to aspherical coefficients. FIG. 17 shows aberrations.

TABLE 25 Example 7, lens data (nd, νd for d-line) Surface number Curvature radius Surface distance nd νd θgF  1 3115.22902 4.400 1.88300 40.76 0.56679  2 349.55385 22.499  3 −388.68497 4.432 1.65113 55.89 0.54672  4 411.65471 2.342  5 429.44340 13.552 1.84139 24.56 0.61274  6 −1689.09587 2.687  7 2385.11397 7.230 1.54072 47.23 0.56511  8 357.62308 26.396 1.43875 94.94 0.53433  9 −318.17967 38.273 10 368.41048 13.143 1.69400 56.29 0.54506 11 ∞ 2.653 12 220.84589 19.997 1.43387 95.18 0.53733 13 3693.07273 0.224 14 313.75805 7.240 1.69895 30.05 0.60290 15 131.42301 28.304 1.43875 94.94 0.53433 16 1146.73703 3.740 17 164.75208 13.328 1.49700 81.54 0.53748 18 414.73079 DD [18] 19 1326.38078 3.183 1.71299 53.87 0.54587 20 67.44942 12.498 21 −286.53431 1.820 1.83481 42.72 0.56486 22 188.08010 2.110 1.84139 24.56 0.61274 23 275.09448 5.138 24 −176.55465 2.032 1.49700 81.54 0.53748 25 100.95140 7.702 1.78472 25.68 0.61621 26 −329.77942 5.500 27 −88.87861 2.000 1.43875 94.94 0.53433 28 714.95128 DD [28] 29 928.29470 7.168 1.43875 94.66 0.53402 30 −166.00053 0.125 31 −1289.47173 8.913 1.43875 94.66 0.53402 32 −103.32262 3.000 1.80000 29.84 0.60178 33 −148.26931 DD [33] 34 308.89930 4.000 1.80000 29.84 0.60178 35 192.07672 6.038 1.43875 94.66 0.53402 36 −1294.71907 0.757 37 196.66541 9.750 1.43875 94.66 0.53402 *38  −720.72252 DD [38] 39 (diaphragm) ∞ 7.195 40 −156.68264 1.520 1.83481 42.72 0.56486 41 842.45166 2.150 1.84139 24.56 0.61274 42 −586.07745 0.200 43 75.34448 4.999 1.56384 60.83 0.54082 44 249.99493 42.069 45 −2883.82574 2.000 1.80610 33.27 0.58845 46 94.42916 3.286 47 −178.38958 2.280 1.95906 17.47 0.65993 48 −87.12464 4.073 49 51.00959 5.290 1.77250 49.62 0.55186 50 −121.12174 1.222 1.53172 48.84 0.56558 51 38.98139 3.994 52 −1400.07367 3.970 1.63854 55.38 0.54858 53 −42.71093 1.000 1.95375 32.32 0.59015 54 98.29809 13.516 55 107.32507 4.265 1.84139 24.56 0.61274 56 −99.07220 8.352 57 −142.68824 4.922 1.51200 52.12 0.56018 58 21.77806 18.000 1.49700 81.54 0.53748 59 37.19255 1.682 60 52.96086 7.467 1.49700 81.54 0.53748 61 −45.25620 1.200 2.00100 29.13 0.59952 62 −177.03293 9.775 63 49.57904 6.438 1.51742 52.43 0.55649 64 −157.84741 2.000 65 ∞ 1.500 1.51633 64.14 0.53531 66 ∞ 0.000 67 ∞ 3.690 1.51633 64.05 0.53463 68 ∞ 32.964

TABLE 26 Example 7, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom magnification 1.0 3.8 19.6 f′ 35.753 137.290 700.753 FNo. 2.93 2.93 4.80 2ω[°] 44.0 11.6 2.4

TABLE 27 Example 7, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 6.643 87.122 121.889 DD [28] 242.174 135.517 5.350 DD [33] 24.794 8.161 2.147 DD [38] 2.646 45.457 146.871

TABLE 28 Example 7, aspherical coefficient Surface number 38 KA 1.0000000E+00 A3 0.0000000E+00 A4 −2.0798385E−08  A5 1.4657683E−08 A6 −3.2730034E−09  A7 3.7528927E−10 A8 −2.3490790E−11  A9 7.3529647E−13 A10 −3.8695741E−15  A11 −4.2162522E−16  A12 7.4099281E−18 A13 2.5167013E−19 A14 −1.1222166E−20  A15 1.6156810E−22 A16 −8.4641640E−25 

A zoom lens according to Example 8 is described next. FIG. 8 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 8. The zoom lens according to Example 8 has the same lens number configuration as that of the zoom lens according to Example 4. Table 29 shows basic lens data of the zoom lens according to Example 8, Table 30 shows data relating to specifications, Table 31 shows data relating to surface distances that change, and Table 32 shows data relating to aspherical coefficients. FIG. 18 shows aberrations.

TABLE 29 Example 8, lens data (nd, vd for d-line) Surface number Curvature radius Surface distance nd vd θgF   1 3419.25761 4.400 1.88300 40.76 0.56679   2 268.72262 22.500   3 −325.39718 4.400 1.65113 55.89 0.54672   4 849.27595 1.590   5 554.83719 12.404 1.84139 24.56 0.61274   6 −772.13620 2.583   7 2822.49348 7.230 1.54072 47.23 0.56511   8 349.62856 25.000 1.43875 94.94 0.53433   9 −324.61950 37.610  10 342.27383 13.390 1.69400 56.29 0.54506  11 ∞ 1.200  12 221.03333 18.892 1.43387 95.18 0.53733  13 3787.89946 0.150  14 296.51832 7.228 1.69895 30.05 0.60290  15 125.50723 27.114 1.43875 94.94 0.53433  16 1067.28694 1.925  17 160.13272 13.806 1.49700 81.54 0.53748  18 439.05795 DD [18]  19 2935.50028 2.539 1.71299 53.87 0.54587  20 61.35000 10.412  21 −282.10249 1.820 1.83481 42.72 0.56486  22 216.47851 1.663 1.84139 24.56 0.61274  23 266.36370 5.213  24 −160.05160 2.032 1.49700 81.54 0.53748  25 96.07282 8.233 1.78472 25.68 0.61621  26 −320.14787 5.500  27 −89.66922 2.000 1.43875 94.94 0.53433  28 −1822.66535 DD [28]  29 819.89128 7.442 1.43875 94.66 0.53402  30 −159.42426 0.125  31 −1769.47221 9.550 1.43875 94.66 0.53402  32 −99.13897 3.000 1.80000 29.84 0.60178  33 −145.00629 DD [33]  34 329.57600 4.000 1.80000 29.84 0.60178  35 207.75429 6.202 1.43875 94.66 0.53402  36 −1286.25470 0.757  37 193.19837 9.750 1.43875 94.66 0.53402 *38 −747.54203 DD [38]  39 (diaphragm) ∞ 7.178  40 −150.83111 1.520 1.83481 42.72 0.56486  41 1285.21087 2.578 1.84139 24.56 0.61274  42 −402.71362 0.200  43 75.19456 4.658 1.56384 60.83 0.54082  44 233.70941 33.600  45 −3742.13758 2.416 1.80610 33.27 0.58845  46 103.10491 3.370  47 −184.64656 2.369 1.95906 17.47 0.65993  48 −91.36101 15.145  49 49.98841 4.815 1.77250 49.62 0.55186  50 −111.26701 1.360 1.53172 48.84 0.56558  51 36.04071 4.796  52 −1102.24855 3.551 1.63854 55.38 0.54858  53 −38.37127 1.000 1.95375 32.32 0.59015  54 91.96782 25.244  55 84.97889 4.905 1.84139 24.56 0.61274  56 −116.46246 1.178  57 −334.60113 4.613 1.51200 52.12 0.56018  58 23.51602 17.561 1.49700 81.54 0.53748  59 32.71339 2.339  60 50.00026 10.184 1.49700 81.54 0.53748  61 −35.25465 1.200 2.00100 29.13 0.59952  62 −170.98964 1.561  63 79.30993 6.391 1.51742 52.43 0.55649  64 −57.85791 2.000  65 ∞ 1.500 1.51633 64.14 0.53531  66 ∞ 0.000  67 ∞ 3.690 1.51633 64.05 0.53463  68 ∞ 33.445

TABLE 30 Example 8, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom magnification 1.0 3.8 19.6 f′ 34.588 132.820 677.934 FNo. 2.90 2.90 4.87 2ω[°] 44.0 11.6 2.4

TABLE 31 Example 8, zoom distance Wide angle end Intermediate position Telephoto end DD [18] 5.628 82.422 114.895 DD [28] 240.928 131.248 4.160 DD [33] 34.219 23.606 2.072 DD [38] 2.586 46.085 162.234

TABLE 32 Example 8, aspherical coefficient Surface number 38 KA  1.0000000E+00 A3  0.0000000E+00 A4  4.9456135E−09 A5  2.3747287E−10 A6 −1.9805341E−11 A7 −3.1856119E−13 A8  1.9296610E−13 A9 −1.6150477E−14 A10  5.7506215E−16 A11 −7.9406340E−18 A12  4.5796409E−20 A13 −4.6008535E−21 A14  1.8723305E−22 A15 −2.6908389E−24 A16  1.2982256E−26

A zoom lens according to Example 9 is described next. FIG. 9 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 9. The zoom lens according to Example 9 has the same lens number configuration as that of the zoom lens according to Example 4. Table 33 shows basic lens data of the zoom lens according to Example 9, Table 34 shows data relating to specifications, Table 35 shows data relating to surface distances that change, and Table 36 shows data relating to aspherical coefficients. FIG. 19 shows aberrations.

TABLE 33 Example 9, lens data (nd, vd for d-line) Surface number Curvature radius Surface distance nd vd θgF  1 2717.73485 5.700 1.88300 40.76 0.56679  2 380.86224 17.798  3 −726.84477 7.258 1.77250 49.60 0.55212  4 292.30100 15.088 1.84139 24.56 0.61274  5 3628.20361 2.930  6 2431.82575 7.530 1.54072 47.23 0.56511  7 371.94500 25.499 1.43875 94.94 0.53433  8 −340.46372 40.037  9 396.43767 12.437 1.77250 49.60 0.55212  10 ∞ 1.767  11 219.67124 18.668 1.43387 95.18 0.53733  12 2215.77255 1.371  13 369.04550 7.283 1.69895 30.13 0.60298  14 138.62300 27.558 1.43875 94.94 0.53433  15 3628.23215 1.114  16 165.94924 15.000 1.49700 81.54 0.53748  17 529.27566 DD [17]  18 1907.28239 3.250 1.69400 56.29 0.54506  19 65.14127 10.408  20 −551.87594 2.089 1.83481 42.72 0.56486  21 133.34200 3.000 1.84139 24.56 0.61274  22 225.37347 6.588  23 −142.82782 2.108 1.49700 81.54 0.53748  24 97.56200 8.061 1.75520 27.51 0.61033  25 −346.22505 5.500  26 −88.09661 2.000 1.43875 94.94 0.53433  27 2023.15419 DD [27]  28 764.60970 7.656 1.43875 94.66 0.53402  29 −160.39950 0.125  30 −2955.12791 9.628 1.43875 94.66 0.53402  31 −101.71700 3.000 1.80000 29.84 0.60178  32 −149.23719 DD [32]  33 343.80179 4.000 1.80000 29.84 0.60178  34 215.03300 6.274 1.43875 94.66 0.53402  35 −950.99135 0.757  36 207.51344 9.750 1.43875 94.66 0.53402 *37 −945.77432 DD [37]  38 (diaphragm) ∞ 6.570  39 −121.16239 1.520 1.83481 42.72 0.56486  40 890.64800 1.744 1.84139 24.56 0.61274  41 2481.54127 0.201  42 71.95464 6.910 1.56883 56.04 0.54853  43 −783.03743 37.160  44 −3949.97334 2.001 1.91100 35.22 0.58360  45 79.02038 6.315  46 −136.72834 2.364 1.94595 17.98 0.65460  47 −84.05991 0.300  48 39.78194 5.517 1.74950 35.28 0.58704  49 −605.08400 1.211 1.53172 48.84 0.56558  50 43.19462 7.880  51 471.91802 4.027 1.67790 55.34 0.54726  52 −43.48600 1.001 1.91100 35.22 0.58360  53 72.66977 12.993  54 88.25253 5.643 1.84139 24.56 0.61274  55 −114.64819 5.753  56 −169.31860 2.927 1.51200 52.12 0.56018  57 21.49700 17.948 1.49700 81.54 0.53748  58 39.43278 1.615  59 46.61676 10.195 1.49700 81.54 0.53748  60 −35.78600 2.572 2.00069 25.46 0.61364  61 −180.29164 10.205  62 48.67158 7.159 1.75550 45.59 0.55875  63 239.34644 2.000  64 ∞ 1.500 1.51633 64.14 0.53531  65 ∞ 0.000  66 ∞ 3.690 1.51633 64.14 0.53531  67 ∞ 32.404

TABLE 34 Example 9, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom magnification 1.0 3.8 19.6 f′ 35.351 135.746 692.872 FNo. 2.85 2.85 4.86 2ω[°] 44.6 11.8 2.4

TABLE 35 Example 9, zoom distance Wide angle end Intermediate position Telephoto end DD [17] 10.362 89.256 123.753 DD [27] 240.405 133.295 5.060 DD [32] 26.561 10.750 2.240 DD [37] 3.448 47.476 149.724

TABLE 36 Example 9, aspherical coefficient Surface number 37 KA 1.0000000E+00 A3 0.0000000E+00 A4 4.6291418E−09 A5 −2.5245283E−11  A6 1.8599768E−12 A7 −1.8274275E−13  A8 1.2282884E−15 A9 4.1929562E−16 A10 −9.0843634E−18  A11 −2.8977192E−19  A12 2.0924759E−21 A13 3.7948885E−22 A14 −4.1745995E−24  A15 −1.3050865E−25  A16 1.9473717E−27

A zoom lens according to Example 10 is described next. FIG. 10 provides cross-sectional views illustrating a lens configuration of the zoom lens according to Example 10. The zoom lens according to Example 10 has the same lens number configuration as that of the zoom lens according to Example 4. Table 37 shows basic lens data of the zoom lens according to Example 10, Table 38 shows data relating to specifications, Table 39 shows data relating to surface distances that change, and Table 40 shows data relating to aspherical coefficients. FIG. 20 shows aberrations.

TABLE 37 Example 10, lens data (nd, vd for d-line) Surface number Curvature radius Surface distance nd vd θgF  1 2821.04454 5.700 1.88300 40.76 0.56679  2 381.28602 17.714  3 −749.98024 7.258 1.77250 49.60 0.55212  4 287.45401 15.400 1.84139 24.56 0.61274  5 3786.57187 3.037  6 2684.13160 7.258 1.54072 47.23 0.56511  7 375.07381 25.623 1.43875 94.94 0.53433  8 −336.45223 40.110  9 387.29043 12.707 1.77250 49.60 0.55212  10 ∞ 1.200  11 218.89802 18.721 1.43387 95.18 0.53733  12 2189.41419 1.633  13 390.73134 7.280 1.69895 30.13 0.60298  14 138.96143 27.412 1.43875 94.94 0.53433  15 3635.93962 4.732  16 163.67600 15.000 1.49700 81.54 0.53748  17 526.91202 DD [17]  18 2249.39184 3.250 1.69400 56.29 0.54506  19 65.53556 10.119  20 −549.71572 1.820 1.83481 42.72 0.56486  21 133.34592 3.000 1.84139 24.56 0.61274  22 229.66815 6.263  23 −144.76978 2.032 1.49700 81.54 0.53748  24 96.97187 7.943 1.75520 27.51 0.61033  25 −349.60908 5.500  26 −88.00025 2.000 1.43875 94.94 0.53433  27 1998.83442 DD [27]  28 760.48326 7.677 1.43875 94.66 0.53402  29 −159.54485 0.125  30 −2858.23392 9.662 1.43875 94.66 0.53402  31 −101.02816 3.000 1.80000 29.84 0.60178  32 −149.81389 DD [32]  33 340.11532 4.000 1.80000 29.84 0.60178  34 219.50376 6.260 1.43875 94.66 0.53402  35 −907.02141 0.810  36 211.78810 9.785 1.43875 94.66 0.53402 *37 −1035.82026 DD [37]  38 (diaphragm) ∞ 8.841  39 −154.31467 1.520 1.83481 42.72 0.56486  40 866.36903 1.894 1.84139 24.56 0.61274  41 ∞ 0.200  42 70.46066 5.210 1.57250 57.74 0.54568  43 249.98594 37.750  44 −1045.94314 2.023 1.88100 40.14 0.57010  45 126.19585 3.026  46 −249.99766 2.482 1.95906 17.47 0.65993  47 −106.36791 2.508  48 46.20707 6.695 1.78800 47.37 0.55598  49 −137.32023 1.265 1.51200 52.12 0.56018  50 40.99770 7.881  51 −3794.31214 3.748 1.66999 51.72 0.55362  52 −44.84376 1.102 1.95375 32.32 0.59015  53 62.98844 12.025  54 72.84718 9.864 1.84139 24.56 0.61274  55 −141.37310 4.543  56 −127.87204 3.368 1.51200 52.12 0.56018  57 21.05592 17.703 1.49700 81.54 0.53748  58 34.99882 2.028  59 50.00097 8.232 1.49700 81.54 0.53748  60 −36.26075 1.300 2.00100 29.13 0.59952  61 −139.97480 9.510  62 59.29004 7.408 1.61405 54.99 0.55092  63 −118.86952 2.000  64 ∞ 1.500 1.51633 64.14 0.53531  65 ∞ 0.000  66 ∞ 3.690 1.51633 64.05 0.53463  67 ∞ 33.351

TABLE 38 Example 10, specifications (d-line) Wide angle end Intermediate position Telephoto end Zoom magnification 1.0 3.8 19.6 f′ 35.348 135.736 692.819 FNo. 2.85 2.85 4.75 2ω[°] 44.2 11.8 2.4

TABLE 39 Example 10, zoom distance Wide angle end Intermediate position Telephoto end DD [17] 7.230 87.035 121.397 DD [27] 241.996 135.033 4.977 DD [32] 24.645 8.820 2.229 DD [37] 2.753 45.735 148.020

TABLE 40 Example 10, aspherical coefficient Surface number 37 KA 1.0000000E+00 A3 0.0000000E+00 A4 5.4418965E−09 A5 −2.8145484E−09  A6 4.9748646E−10 A7 −3.8597730E−11  A8 1.4954479E−12 A9 −2.9419974E−14  A10 3.5436025E−16 A11 −1.8610537E−18  A12 −3.0741467E−19  A13 9.2999539E−21 A14 1.1878876E−22 A15 −7.1645004E−24  A16 6.8958760E−26

Table 41 shows values corresponding to the conditional expressions (1) to (9) of the zoom lenses according to Examples 1 to 10. In all examples, the d-line is used as the reference wavelength. The values shown in Table 41 provided below are for the reference wavelength.

TABLE 41 Expression No. Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 (1) (L2bpr + L2cnf)/(L2bpr − L2cnf) −0.301 −0.301 −0.298 −0.075 0.304 (2) f2/f2a 0.261 0.261 0.262 0.493 0.449 (3) f2/f2b 0.403 0.403 0.400 0.358 0.204 (4) f2*(f2cp_nd − f2cn_nd)*(1/L2cnp) −0.164 −0.164 −0.163 −0.135 −0.137 (5) f1c_νd_ave 90.6 86.1 95.0 82.0 82.0 (6) f1c_θ gF_ave 0.536 0.537 0.537 0.539 0.539 (7) f1/f1c 1.014 1.025 1.011 1.037 1.060 (8) (L1ar + L1bf)/(L1ar − L1bf) −0.072 −0.046 −0.108 −0.208 −0.253 (9) d2/tt1 0.084 0.085 0.084 0.099 0.096 Expression No. Conditional expression Example 6 Example 7 Example 8 Example 9 Example 10 (1) (L2bpr + L2cnf)/(L2bpr − L2cnf) 0.266 0.218 0.249 0.188 0.198 (2) f2/f2a 0.459 0.470 0.525 0.476 0.480 (3) f2/f2b 0.254 0.279 0.282 0.241 0.240 (4) f2*(f2cp_nd − f2cn_nd)*(1/L2cnp) −0.131 −0.134 −0.138 −0.122 −0.124 (5) f1c_νd_ave 82.0 82.0 82.0 80.3 80.3 (6) f1c_θ gF_ave 0.539 0.539 0.539 0.540 0.540 (7) f1/f1c 1.042 1.026 1.012 1.069 1.064 (8) (L1ar + L1bf)/(L1ar − L1bf) −0.134 −0.053 −0.095 −0.312 −0.326 (9) d2/tt1 0.103 0.107 0.112 0.086 0.084

Referring to the above data, it is found that all the zoom lenses according to

Examples 1 to 10 are high-performance zoom lenses which satisfy the conditional expressions (1) to (9), which have high magnification of 15 or more and a F-number of 5 or less at the telephoto end, and whose aberrations have been properly corrected.

An imaging apparatus according to an embodiment of the invention is described next. FIG. 21 is a schematic configuration diagram of an imaging apparatus using a zoom lens according to an embodiment of the invention, as an example of an imaging apparatus according to an embodiment of the invention. FIG. 21 schematically illustrates respective lens groups. The imaging apparatus may be, for example, a video camera or an electronic still camera including a solid-state imaging element, such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

An imaging apparatus 10 illustrated in FIG. 21 includes a zoom lens 1, a filter 6 that is arranged on the image side of the zoom lens 1 and that has a function of a low pass filter or the like, an imaging element 7 arranged on the image side of the filter 6, and a signal processing circuit 8. The imaging element 7 is for converting an optical image formed by the zoom lens 1 into an electric signal. For example, CCD or CMOS can be used for the imaging element 7. The imaging element 7 is arranged such that an imaging surface of the imaging element 7 is aligned with the image surface of the zoom lens 1.

An image captured by the zoom lens 1 forms an image on the imaging surface of the imaging element 7, an output signal from the imaging element 7 relating to the image is arithmetically processed by the signal processing circuit 8, and the image is displayed on a display device 9.

Since the imaging apparatus 10 according to this embodiment includes the zoom lens 1 according to the invention, an image with high magnification and high image quality can be obtained.

While the invention has been described above by using the embodiments and examples; however, the invention is not limited to the embodiments and examples, and may be modified in various ways. For example, the values of curvature radius, surface distance, refractive index, and/or Abbe number of each lens are not limited to the values provided in each of the numerical examples, and may have other values.

REFERENCE SIGNS LIST

-   zoom lens -   filter -   imaging element -   signal processing circuit -   display device -   imaging apparatus -   G1 first lens group -   G1 a 1 a lens group -   G1 b 1 b lens group -   G1 c 1 c lens group -   G2 second lens group -   G3 third lens group -   G4 fourth lens group -   G5 fifth lens group -   PP1, PP2 optical member -   L1 a to L5 o lens -   Sim image surface -   St aperture diaphragm -   wa axial ray -   wb ray at maximum angle of view -   Z optical axis 

What is claimed is:
 1. A zoom lens, consisting of: in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive refractive power, wherein during zooming, the first lens group is fixed relative to an image surface, wherein during zooming from a wide angle end to a telephoto end, a distance between the first lens group and the second lens group constantly increases, a distance between the second lens group and the third lens group constantly decreases, and a distance between the third lens group and the fourth lens group at the telephoto end is smaller than a distance between the third lens group and the fourth lens group at the wide angle end, wherein the second lens group consists of, in order from the object side, a first lens component, a second lens component, a third lens component, and a fourth lens component, wherein the first lens component is a 2a negative lens having a concave surface that faces an image side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the object side of the 2a negative lens, wherein the second lens component is a cemented lens in which a 2bn biconcave lens and a 2bp positive meniscus lens are cemented in that order from the object side and which entirely has a negative refractive power, wherein the third lens component is a cemented lens in which a 2cn biconcave lens and a 2cp positive lens are cemented in that order from the object side, and wherein the fourth lens component is a 2d negative lens having a concave surface that faces the object side and that has a smaller absolute value of a curvature radius than an absolute value of a curvature radius of a surface on the image side of the 2d negative lens.
 2. The zoom lens according to claim 1, wherein during zooming, the fifth lens group is fixed relative to the image surface, and wherein during zooming from the wide angle end to the telephoto end, a 3-4 composite lens group composed of the third lens group and the fourth lens group, and the second lens group simultaneously pass through respective points at which imaging magnifications of the 3-4 composite lens group and the second lens group are −1.
 3. The zoom lens according to claim 1, wherein during zooming from the wide angle end to the telephoto end, the distance between the third lens group and the fourth lens group decreases, increases, and then decreases.
 4. The zoom lens according to claim 1, wherein the 2a negative lens is a meniscus lens.
 5. The zoom lens according to claim 1, wherein the following conditional expression (1) is satisfied −1<(L2bpr+L2cnf)/(L2bpr−L2cnf)<1   (1), where L2bpr is a curvature radius of a surface on the image side of the 2bp positive meniscus lens, and L2cnf is a curvature radius of a surface on the object side of the 2cn biconcave lens.
 6. The zoom lens according to claim 1, wherein the following conditional expressions (2) and (3) are satisfied 0.2<f2/f2a<0.6   (2), and 0.1<f2/f2b<0.6   (3), where f2 is a focal length for a d-line of the second lens group, f2a is a focal length for the d-line of the first lens component, and f2b is a focal length for the d-line of the second lens component.
 7. The zoom lens according to claim 1, wherein the following conditional expression (4) is satisfied −0.3<f2×(f2cp_nd−f2cn_nd)×(1/L2cnp)<−0.1   (4), where f2 is the focal length for the d-line of the second lens group, f2cp_nd is a refractive index for the d-line of the 2cp positive lens, f2cn_nd is a refractive index for the d-line of the 2cn biconcave lens, and L2cnp is a curvature radius of a cemented surface of the 2cn biconcave lens and the 2cp positive lens.
 8. The zoom lens according to claim 1, wherein the first lens group consists of, in order from the object side, a 1 a lens group fixed relative to the image surface during focusing and having a negative refractive power, a 1 b lens group being movable along an optical axis during focusing and having a positive refractive power, and a 1 c lens group fixed relative to the image surface during focusing and having a positive refractive power, and wherein the 1 c lens group has on the most image side four lenses of, in order from the object side, a positive lens, a cemented lens in which a negative meniscus lens having a convex surface facing the object side and a positive lens are cemented in that order from the object side, and a positive meniscus lens having a convex surface facing the object side.
 9. The zoom lens according to claim 8, wherein the following conditional expressions (5) and (6) are satisfied 75<f1c_vd_ave<96   (5), and 0.5<f1c_θgF_ave<0.6   (6), where f1c_vd_ave is an average value of Abbe numbers for the d-line of the positive lenses included in the 1 c lens group, and f1c_θgF_ave is an average value of partial dispersion ratios of the positive lenses included in the 1 c lens group.
 10. The zoom lens according to claim 8, wherein the following conditional expression (7) is satisfied 0.8<f1/f1c<1.2   (7), where f1is a focal length for the d-line of the first lens group, and f1c is a focal length for the d-line of the 1 c lens group.
 11. The zoom lens according to claim 8, wherein the number of positive lenses included in the 1 b lens group and the 1 c lens group is five in total.
 12. The zoom lens according to claim 11, wherein the 1 b lens group consists of, in order from the object side, a cemented lens in which a negative meniscus lens and a biconvex lens are cemented in that order from the object side, and a biconvex lens, and wherein the 1 c lens group consists of, in order from the object side, a biconvex lens, a cemented lens in which a negative meniscus lens and a positive meniscus lens are cemented in that order from the object side, and a positive meniscus lens.
 13. The zoom lens according to claim 11, wherein the 1 b lens group consists of a cemented lens in which a negative meniscus lens and a biconvex lens are cemented in that order from the object side, and wherein the 1 c lens group consists of, in order from the object side, a positive lens having a convex surface facing the object side, a positive meniscus lens, a cemented lens in which a negative meniscus lens and a positive meniscus lens are cemented in that order from the object side, and a positive meniscus lens.
 14. The zoom lens according to claim 8, wherein the 1 a lens group consists of, in order from the object side, a negative meniscus lens, a biconcave lens, and a positive lens.
 15. The zoom lens according to claim 5, wherein the following conditional expression (1-1) is satisfied −0.6<(L2bpr+L2cnf)/(L2bpr−L2cnf)<0.6   (1-1).
 16. The zoom lens according to claim 6, wherein the following conditional expression (2-1) and/or conditional expression (3-1) are satisfied 25<f2/f2a<0.55   (2-1), and/or 0.2<f2/f2b<0.5   (3-1).
 17. The zoom lens according to claim 7, wherein the following conditional expression (4-1) is satisfied −0.2<f2×(f2cp_nd−f2cn_nd)×(1/L2cnp)<−0.12   (4-1).
 18. The zoom lens according to claim 9, wherein the following conditional expression (5-1) and/or conditional expression (6-1) are satisfied 80<f1c_vd_ave<96   (5-1), and/or 0.52<f1c_θgF_ave<0.56   (6-1).
 19. The zoom lens according to claim 10, wherein the following conditional expression (7-1) is satisfied 0.9<f1/f1c<1.1   (7-1).
 20. An imaging apparatus comprising the zoom lens according to claim
 1. 